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Finding the Fourth Proportional to 860.30, 1,290.43 and 211.03

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Solution

The fourth proportional to 860.30, 1,290.43 and 211.03 is: 316.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.30 : 1,290.43 = 211.03 : x
  2. Step 2: Convert to fraction form
    860.30/1,290.43 = 211.03/x
  3. Step 3: Cross multiply
    860.30x = 1,290.43 × 211.03
  4. Step 4: Simplify right side
    860.30x = 272,319.44
  5. Step 5: Solve for x
    x = 272,319.44/860.30
  6. Step 6: Final answer
    x = 316.54

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.